Biology subjects

Milla, R.

Publications and source records attributed to Milla, R..

3 recordsLinked to original sources

bioRxiv2023

BEING A TREE CROP INCREASES THE ODDS OF EXPERIENCING YIELD DECLINES IRRESPECTIVE OF POLLINATOR DEPENDENCE

Crop yields, i.e., harvestable production per unit of cropland area, are in decline for a number of crops and regions, but the drivers of this process are poorly known. Global decreases in pollinator abundance and diversity have been proposed as a major driver of yield declines in crops that depend on animals, mostly bees, to produce fruits and seeds. Alternatively, widespread tree mortality has been directly and indirectly related to global climate change, which could also explain yield decreases in tree crops. As tree crops are expected to be more dependent on pollinators than other crop types, disentangling the relative influence of growth form and pollinator dependence is relevant to identify the ultimate factors driving yield declines. Yield decline, defined here as a negative average annual yearly change in yield from 1961 to 2020, was measured in 4270 time series, involving 136 crops and 163 countries and territories. About one-fourth of all time series showed declines in crop yield, a characteristic associated with both high pollinator dependence and a tree growth form. Because pollinator dependence and plant growth form were partially correlated, we disentangled the effect of each of these two predictors using a series of generalized linear mixed models that evaluated direct and indirect associations. Our analyses revealed a stronger association of yield decline with growth form than with pollinator dependence, a relationship that persisted after partialling out the effect of pollinator dependence. In particular, yield declines were more common among tree than herbaceous and shrub crops in all major regions but in Africa, a continent showing a high incidence of yield declines irrespective of growth form. These results suggest that pollinator decline is not the main reason behind crop productivity loss, but that other factors such as climate change could be already affecting crop yield.

ecology↗

bioRxiv2021

Global mismatches between crop distributions and climate suitability

The selection of new crops and the migration of crop areas are two key strategies for agriculture to cope with climate change and ensure food security in the coming years. However, both rely on the assumption that climate is a major factor determining crop distributions worldwide. Here, we show that the current global distributions of nine of twelve major crops strongly diverge from their modelled climatic suitability for yields, after controlling for technology, agricultural management and soil conditions. Comparing the climatic niches of crops and their wild progenitors reveals that climate suitability is higher outside the native climatic range for six of these nine crops while all of them are farmed predominantly in their native ranges. These results show that agricultural strategies coping with climate change will be unsuccessful unless they fully consider the social, cultural, and ecological factors underpinning crop distributions.

ecology↗

bioRxiv2020

Global Root Traits (GRooT) Database

MotivationTrait data are fundamental to quantitatively describe plant form and function. Although root traits capture key dimensions related to plant responses to changing environmental conditions and effects on ecosystem processes, they have rarely been included in large-scale comparative studies and global models. For instance, root traits remain absent from nearly all studies that define the global spectrum of plant form and function. Thus, to overcome conceptual and methodological roadblocks preventing a widespread integration of root trait data into large-scale analyses we created the Global Root Trait (GRooT) Database. GRooT provides ready-to-use data by combining the expertise of root ecologists with data mobilization and curation. Specifically, we (i) determined a set of core root traits relevant to the description of plant form and function based on an assessment by experts, (ii) maximized species coverage through data standardization within and among traits, and (iii) implemented data quality checks. Main types of variables containedGRooT contains 114,222 trait records on 38 continuous root traits. Spatial location and grainGlobal coverage with data from arid, continental, polar, temperate, and tropical biomes. Data on root traits derived from experimental studies and field studies. Time period and grainData recorded between 1911 and 2019 Major taxa and level of measurementGRooT includes root trait data for which taxonomic information is available. Trait records vary in their taxonomic resolution, with sub-species or varieties being the highest and genera the lowest taxonomic resolution available. It contains information for 184 sub-species or varieties, 6,214 species, 1,967 genera and 254 families. Due to variation in data sources, trait records in the database include both individual observations and mean values. Software formatGRooT includes two csv file. A GitHub repository contains the csv files and a script in R to query the database.

ecology↗